Stitch length adjusting means for sewing machines



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Dec. 5, 1961 H. RlTTER ET AL 3,011,462

STITCH LENGTH ADJUSTING MEANS FOR SEWING MACHINES Filed May 18, 1960 2 Sheets-Sheet 1 INVENTORS Hermap Riffer WITNESS Fig.3 Frederick Rogers VMMW wmuw A TORNEY H. RlTTER ET AL 3,011,462

STITCH LENGTH ADJUSTING MEANS FOR SEWING MACHINES Dec. 5, 1961 2 Sheets-Sheet 2 Filed May 18, 1960 s m f Re OJIO VI TU! E 5 B MH MD H mam M m I I n l O! h, m M a f HF WITNESS a (XI/QM United States Patent 3,011,462 STITCH LENGTH ADJUSTING MEANS FOR SEWING MACHINES Herman Ritter, Cranford, and Frederick Rogers, Union,

Elizabeth N.J., a corporation of New Jersey Filed May 18, 1960, Ser. No. 30,033 6 Claims. (Cl. 112-210) This invention relates to sewing machines and particularly to the stitch length adjusting means for the feeding 'mechanism of a sewing machine invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such'detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which: I

FIG. 1 is a fragmentary front elevational view of a sewing machine embodying the present invention,

FIG. 2 is a fragmentary vertical sectional view taken substantially on the line 2-2 of FIG. 1, and,

FIG. 3 is a detail sectional view taken substantially on the line 33 of FIG. 1. 7

With reference to the drawings there is illustrated a portion of the frame of a sewing machine including a bed 1 and a standard 2 rising from one end of the bed and 'includinga front wall 3. Journaled in the bed 1 is a feed advance rock shaft 4 having a crank 5 that is connected at its free end to, the lower end of a pitman 6 which at its upper end is bifurcated to provide a fork 7 receiving a slide element 8 that embraces an eccentric 91 on a main shaft 10. The main shaft 10 is journaled longitudinally of the frame of the machine and is driven in the usual fashion by a belt pulley 11.

Endwise motion of the pitman dimparts oscillation to the feed advance shaft 4. Oscillation imparted to the pitman 6 by the eccentric 9 is converted to endwise motion by means of an anchor link 12 pivotally connected at one end to an intermediate point ofthe pitman 6 and at its other end to a block 13 by a pivot 14. The block 13 is pivotally mounted in the frame of the machine at 15 and is adapted't'o. be swung about the pivot 15 in opposite directions from a center position in which link 12 is parallel to the pitm an 6 at the point in the center of the 'arc of oscillation of the pitman so that substantially no endwise motion is imparted to the pitman 6. As the distance the pivot 15 is moved away from the center position is increased, and as it is moved to opposite sides of, the "center position, the endwise movement of the pitman 6 is reversed to providefor forward and reverse actuation of the feeding mechanism.

The block 13 has a forwardly extending arm 1-6 that passes through an opening 17, the front wall of the standard 2 and into a housing 18 surrounding the opening 16 and secured to the frame in oil-tight relation. A rod 19 having oppositely threaded portions 20 and 21 is mounted in the housing 18 for endwise adjustment and for turning by means of a reduced portion 22 at its lower J i n rs t Th Singer ufa u g C mp y,

of an internally threadedbore on the threaded portion 20 of the rod 19 and has a laterally extending stop arm 29 adapted to be engaged by the arm 16. A second stop 30 is mounted in the same manner on the threaded portion 210i the'rod 19 and has a stop arm 31 adapted to be engaged by'the arm 16.-

. The stops 28 and 30 are disposed on opposite sides 8 of the center position-of the arm 16 and limit swinging of the arm 16 in each direction from the center position to a selected stitch length setting. The stop 30 determines the stitch length forward and the stop 28 determines the. same in reverse. The stops 28 and 30 are also mounted on the rod 19 at an equal distance from the center position so that upon swinging the block 13 from one stop to the other, the feed will be reversed but the stitch length will be the same. Because of the oppositely threaded portions 20 and 21 of the rod 19, the steps 28 and 30 will converge and diverge to .decrease and increa se the stitch length but will always remain the same distance from the center position as the rod 19 is turned.

To indicate the setting of the stitch length, the stop arm 31 carries an indicator 32 that slidably extends through a bore in the wall of the housing 18 and cooperates With indicia (not shown) on a side wall 33 of the housing 18.

The mechanism is biased in the'direction of forward feed by a spring 34 anchored at one end in the standard *2 and connected at ,the'other end to a crank arm 35 on a countershaft journal 36 in and extending through the end wall of ,the standard 2. The crank arm 35 is connected to the block 13 by a link 37. To reverse the feed, there is provided a lever 38 secured on the end of the countershaft 36 and extending around to the front of the standard 2 and terminating in a hand pad 39.

When the stops 28 and 30 are brought together by turning the rod 19 until they both engage the arm 16, the mechanism should be in the center position, that is, the position of zero feed. To correct any errors that may be present, the rod 19 is made adjustable endwise by means of a cylindrical member 40 journaled in the housing 18 on an axis normal to the rod 19 and opposite the bushing 25. The cylindrical member 40 has an eccentric stpd 41 on a axis parallel to and spaced from the axis of the member 40 and entering a-transverse slot 42 in the bushing 25. The bushing 25 is normally locked, by a set serew, 43-. When the set screw 43 is released, turning the cylindrical member 40 will raise or lower the bushing 25;, which will raise or lower the rod-19 The cylindrical member 40 is held in place and locked by a set screw 44.

The present mechanism is adapted to be mounted in a sewing machine in which all the internal mechanism is automatically lubricated. The housing 18 completely seals the opening 17 in the front wall of the standard and the elements projecting from the interior of the frame, that is, the rod 19, indicator 32 and countershaft 36, are all simple cylindrical members having only turning or endwise sliding movement so that the opening can be readily sealed to prevent leaks of oil.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for the purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus set forth the nature of this invention, what we claim herein is:

1. In a feeding mechanism for sewing machines having a frame and a stitch length adjusting mechanism including a block mounted in said frame for varying the feed advance movement from zero to a maximum upon movement of said block away from a center position and for reversing the feed advance movement upon movement of said block in opposite directions from said center position, a rod mounted in said frame for turning and for endwise movement and having an externally threaded portion, a stop having an internally threaded element receiving said rod and cooperating with the threaded portion thereof for movement endwise thereof upon turning of said rod, an arm extending from said block and engaging said stop for limiting movement of said block in one direction away from said center position, a cylindrical member journaled in said frame on an axis normal to said rod, an eccentric stud on the end of said cylindrical member adjacent to said rod on an axis parallel to and spaced from the axis of said cylindrical member, means operatively connecting said stud to said rod for effecting endwise adjustment of said rod upon turning said cylindrical member, and means for releasably locking said cylindrical member in adjusted position.

2. In a feeding mechanism for sewing machines having a frame, a feed advance rock shaft journaled for oscillation in said frame, a pitman, means connecting the end of said pitman to said feed advance rock shaft for imparting oscillation thereto upon endwise movement of said pitman, means for imparting oscillation thereto upon endwise movement of said pitman, means for imparting oscillation to said pitman, a block pivotally mounted in said frame, means for connecting said block to said pitman for imparting endwise movement to said pitman upon oscillation thereof and for varying the amplitude thereof from zero to a maximum upon pivotal adjustment of said block from a center position and for reversing the endwise motion imparted to said pitman upon pivotal adjustment of said block in opposite directions from said center position, a rod mounted in said frame for turning and for endwise movement and having an externally threaded portion, a stop having an internally threaded bore receiving said rod and cooperating with the threaded portion thereof for movement endwise thereof upon turning of said rod, an arm extending from said block and engaging said stop for limiting pivotal adjustment of said block in one direction away from said center position, a cylindrical member journaled in said frame on an axis normal to said rod, an eccentric stud on the end of said cylindrical member adjacent to said rod on an axis parallel to and spaced from the axis of said cylindrical member, means operatively connecting said stud to said rod for effecting endwise adjustment of said rod upon turning said cylindrical member, and means for releasably locking said cylindrical member in adjusted position.

3. In an automatically lubricated sewing machine having a frame defining a closed compartment and adapted to include means for automatically lubricating the mechanism within said compartment, stitch-length adjusting mechanism within said compartment and including a block mounted in said frame for varying the feed advance movement from zero to a maximum upon movement of said block away from a center position and for reversing the feed advance movement upon movement of said block in opposite directions from said center position, a rod mounted in said frame within said compartment for turning and for endwise movement and having an externally threaded portion intermediate its ends and having one end thereof extending through said frame, a stop having an internally threaded bore receiving said rod and cooperating with the threaded portion thereof for movement endwise thereof upon turning of said rod, an arm extending from said block and engaging said stop for limiting movement of said block in one direction away from said center position, a cylindrical member journaled in said frame on an axis normal to said rod, an eccentric stud on the end of said cylindrical member adjacent to said rod on an axis parallel to and spaced from the axis of said cylindrical member, means operatively connecting said stud to said rod for effecting endwise adjustment of said rod upon turning said cylindrical member, and means for releasably locking said cylindrical member in adjusted position.

4. A sewing machine in accordance with claim 3 in which said rod is mounted in a housing releasably secured to said frame in an oil-tight manner and is mounted therein by means of a bushing in a wall of said housing, means securing said rod to said bushing for unitary endwise movement, said bushing having a slot for receiving said eccentric stud for imparting endwise movement to said bushing upon turning said cylindrical member and thereby effecting endwise adjustment of said rod.

5. A sewing machine in accordance with claim 4 in which said rod has a pair of oppositely threaded portions extending in opposite directions from said center posi- 1 tion, said stop is mounted on one of said threaded portions and a second stop is mounted on the other of said threaded portions, said arm on said block engages one of said stops in each direction of movement from said' center position to limit the same in the forward and reverse stitch settings, spring means biasing said block in the direction to effect forward feed, a countershaft journaled in said frame and extending into said compartment, means within said compartment for connecting said countershaft to said block to move said block to reverse feed against the action of said spring and manually actuated means connected to said countershaft on the exterior of said frame.

6. A sewing machine in accordance with claim 3 having an indicator rod mounted on said stop and slidably extending through said frame to the exterior of said compartment for cooperating with indicia on said frame to indicate the stitch length setting of said stop.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain of 1908, 

